From Culture Change site:
You. Will. Not. Be. Able. To. Get. Food. Need this be spelled out any more plainly? It is time to consider that the stage has been set for petroleum-induced famine.
We have “innocently” accommodated rising population with greater and greater food production via technology and the profit motive. But now we have run out of room to grow, as biotechnology, for example, has severe limitations — major ones being petroleum dependence and topsoil loss. The biggest wild card for our existence is climate change, as we see with floods and other extreme weather affecting our food supply.
We are headed for massive shortages of food and other essentials, mainly brought about by the depletion of geological fossil reserves of cheap energy and water. The situation is demonstrated regularly with easy arithmetic based on statistical indicators from the United Nations, Worldwatch Institute, World Resources Institute, Earth Policy Institute, and numerous governments. Usually the full force of the message is offset by predictions of huge rises in future human population growth that are simple extrapolations of historical trends.
Finally, a few other sites are ringing the alarm bells.